Although the Ki-100-I arrived at the tail end of the war, it still left behind an impressive legacy. Using the Ki-61 as its foundation, the Ki-100-I was powered by the Mitsubishi® Ha 112-II radial engine, which delivered an impressive 1,500 hp at takeoff. The plane's power and maneuverability made it an immediate addition to several IJAAF Flight Regiments, including the celebrated 5th and 244th.